TWI508372B - Antenna structure and wireless communication device using the same - Google Patents

Description

Antenna structure and wireless communication device using the same

The present invention relates to an antenna, and more particularly to an antenna structure and a wireless communication device using the same.

With the rapid development of wireless communication technology and information processing technology and the increasing standard of living of people, portable wireless communication devices such as mobile phones and personal digital assistants (PDAs) are competing to appear and enter thousands of households. Consumers can enjoy the convenience brought by high technology anytime and anywhere, making these portable wireless communication devices become an indispensable part of modern people's daily life.

Among these wireless communication devices, an antenna device for transmitting and receiving radio waves to transmit and exchange radio data signals is undoubtedly one of the most important components in a wireless communication device. In a portable electronic device, since the antenna is generally small in size, when the user holds the portable electronic device in a different posture or changes in the surrounding environment (such as changes in temperature, humidity, etc.), The working environment of the antenna causes a large change, so that the frequency of the signal transmission and reception of the antenna changes, that is, the frequency offset effect. When the frequency offset effect occurs, the efficiency of the antenna wireless communication device to send and receive a specific frequency of the working signal is reduced, which may not meet the actual use requirements.

In view of this, it is necessary to provide an antenna structure capable of accurately and stably transmitting and receiving signals.

In addition, it is also necessary to provide a wireless communication device to which the antenna structure is applied.

An antenna structure includes a first antenna portion and a second antenna portion, the first antenna portion includes a first radiator, and the first radiator is configured to transmit and receive wireless with a first operating frequency a second antenna portion including a second radiator for transmitting and receiving a wireless signal having a second operating frequency, the second radiator being disposed parallel to the first radiator and The first radiator is spaced apart from the first radiator to cause a coupling effect of the first radiator and the second radiator to obtain a new operating frequency band of the antenna structure.

A wireless communication device includes a base body and an antenna structure. The base body is provided with a ground end and a feed end. The ground end and the feed end are connected to an antenna structure, and the antenna structure includes a first day. a first antenna portion, the first antenna portion includes a first radiator, the first radiator is configured to transmit and receive a wireless signal having a first operating frequency, and the second antenna portion includes a second radiator for transmitting and receiving a wireless signal having a second operating frequency, the second radiator being disposed parallel to the first radiator and spaced apart from the first radiator So that the first radiator and the second radiator generate a coupling effect to obtain a new operating frequency band of the antenna structure.

Compared with the prior art, the radiators of the first antenna portion and the second antenna portion of the antenna structure are parallel to each other and separated by a specific distance, and the magnetic coupling generated by the operating current can effectively improve the first The matching of the resonant modes of the antenna portion and the resonance mode synthesis of the second antenna portion to generate a wider operating band can effectively compensate for the negative influence of the frequency offset effect on the working signals for transmitting and receiving specific frequencies.

100‧‧‧Antenna structure

12‧‧‧First radiator

124‧‧‧Second connection

14‧‧‧First grounding

30‧‧‧second antenna unit

322‧‧‧First zigzag

322b‧‧‧short end

326‧‧‧ Second zigzag

326b‧‧‧longer

36‧‧‧Second Feeding Department

210‧‧‧ end face

230‧‧‧ side

250‧‧‧ first plane

254‧‧‧Feeding end

10‧‧‧First antenna unit

122‧‧‧First connection

126‧‧‧ Third connection

16‧‧‧First Feeding Department

32‧‧‧Second radiator

322a‧‧‧Longer end

324‧‧‧Transition Department

326a‧‧‧Short section

34‧‧‧Second grounding

200‧‧‧ base

220‧‧‧ top surface

240‧‧‧ gap

252‧‧‧ Grounding

260‧‧‧ second plane

1 is a schematic diagram of an antenna structure mounted on a wireless communication device in accordance with a preferred embodiment of the present invention.

2 is a perspective view of an antenna structure in accordance with a preferred embodiment of the present invention.

Fig. 3 is a view showing the main dimensions of the first antenna portion and the second antenna portion of the antenna structure according to the preferred embodiment of the present invention in an unfolded state.

4 is a schematic diagram of return loss (RL) of an antenna structure in accordance with a preferred embodiment of the present invention.

1 and 2 illustrate an antenna structure 100 in accordance with a preferred embodiment of the present invention, which is applicable to a wireless communication device having a Bluetooth function. The antenna structure 100 is disposed on a base 200 of the wireless communication device. The base 200 can be a part of a printed circuit board (PCB) of a wireless communication device.

The base body 200 is substantially in the shape of a rectangular parallelepiped, and includes an end surface 210, a top surface 220 and a side surface 230, and forms a "L" through the base body 200 at the joint of the end surface 210, the top surface 220 and the side surface 230. A notch 240 is formed, and the notch 240 correspondingly forms a first plane 250 and a second plane 260 perpendicular to the first plane 250 on the base 200. A grounding end 252 and a feeding end 254 are vertically disposed on the first plane 250. The grounding end 252 and the feeding end 254 are both conventionally arranged in a column shape, and the grounding end 252 and the feeding end 254 are electrically connected to the base body 200. The grounding end 252 is grounded for the base body 200 and has a length greater than the length of the feeding end 254. The feeding end 254 can be used for signal feeding of the base body 200.

The antenna structure 100 includes a first antenna portion 10 and a second antenna portion 30. The first antenna portion 10 and the second antenna portion 30 are both disposed in the notch 240 and are located in different planes.

The first antenna portion 10 is a Planar Inverted-F Antenna (PIFA), and includes a first radiator 12, a first ground portion 14, and a first feed portion 16.

The first radiator 12 is an elongated sheet that is disposed parallel to the first plane 250 and has a vertical distance from the first plane 250 of about 2.5 mm. The first radiator 12 includes a first connecting portion 122, a second connecting portion 124 and a third connecting portion 126 which are connected in sequence and have the same width and are disposed in the same plane. The first connecting portion 122 is an elongated piece, the second connecting portion 124 is perpendicular to the first connecting portion 122 and extends away from the top surface 220, and the third connecting portion 126 is vertical. The second connecting portion 124 extends in the direction parallel to the first connecting portion 122 toward the second plane 260 to form an elongated strip having a length shorter than the length of the first connecting portion 122.

The first ground portion 14 is an elongated strip having a width smaller than a width of the first radiator 12 , and the first ground portion 14 is parallel to the second connecting portion 124 . One end of the first grounding portion 14 is vertically disposed on a side of the first radiator 122, and the other end is vertically connected to a central portion of a side of the ground end 252 of the base 200, and passes through the grounding end 252 and the base 200. An electrical connection is established to provide a grounding effect for the first antenna portion 10.

The first feeding portion 16 is a shorter piece having a width corresponding to the width of the first radiator 12, and the first feeding portion 16 is placed in the first direction in parallel with the first ground portion 14. The same side of the radiator 12. And one end of the first feeding portion 16 is vertically connected to the The other end of the first connecting portion 122 is electrically connected to the feeding end 254 of the base 200, and the first antenna portion 10 is used for signal feeding.

The second antenna portion 30 is a loop antenna, and includes a second radiator 32, a second ground portion 34, and a second feed portion 36.

The second radiator 32 is a strip having a width slightly smaller than the width 12 of the first radiator, and is disposed integrally with another plane parallel to the plane of the first radiator 12, And a distance of about 0.4 mm is provided between the two planes. The second radiator 32 includes a first meandering portion 322, a transition portion 324 and a second bent portion 326 which are connected in sequence and have the same width and are disposed in the same plane. The first meandering portion 322 is substantially "L" shaped elongated strip and includes a longer end 322a and a shorter end 322b. The projection of the longer end 322a on the plane of the first radiator 12 is located between the first connecting portion 122 and the third connecting portion 126, and is parallel to the first connecting portion 122 and the third connecting portion 126 The length of the longer end 322a is slightly shorter than the length of the first connecting portion 122. One end of the shorter end 322b is perpendicularly connected to one end of the longer end 322a and extends toward the top surface 220, and the projection of the shorter end 322b on the plane of the first radiator 12 is aligned. Two connecting portions 124. One end of the transition portion 324 is perpendicularly connected to the end of the shorter end 322b, and extends in a direction close to the end surface 210 of the base body 200 to form a straight strip-shaped body parallel to the first connecting portion 122, The projection of the transition portion 324 on the plane of the first radiator 12 is aligned with the end of the first connecting portion 122, and the length of the transition portion 324 and the length of the longer end 332a are greater than the first connecting portion 122. . The second meandering portion 326 is substantially "L" shaped and includes a shorter portion 326a and a longer portion 326b. One end of the shorter portion 326a is perpendicularly connected to the end of the transition portion 324, and the other end extends away from the top surface 220 of the base body 200, and the length of the shorter portion 326a is long. The length of the second connecting portion 124. The longer portion 326b is perpendicularly connected to the other end of the shorter portion 326a, and extends in a direction parallel to the 322a toward the second plane 260 to form a strip having a length slightly longer than the longer end 322a. The piece.

The width of the second ground portion 34 is the same as the width of the second radiator 32 and is disposed parallel to the first ground portion 14. One end of the second grounding portion 34 is perpendicularly connected to the end of the longer portion 326b near the second plane 260, and the other end is perpendicularly connected to the end of the grounding end 252, and passes through the grounding end 252 and the base body 200. An electrical connection is established to provide a grounding effect for the second antenna portion 30.

The second feeding portion 36 is a shorter piece, one end of which is perpendicularly connected to one side of the longer end 322a, and the other end of which is vertically connected to the side of the first feeding portion 16 and passes through the first The feeding portion 16 is electrically connected to the feeding end 254 to provide signal feeding to the second antenna portion 30. It can be understood that the length of the second feeding portion 36 is the distance between the second radiator 32 and the first radiator 12.

Referring to FIG. 3, it is determined by experiment that the preferred size of one of the antenna structures 100 in the present embodiment is as follows. The lengths of the first connecting portion 122, the second connecting portion 124, and the third connecting portion 126 of the first antenna portion 10 are respectively 21mm, 1mm and 3.7mm. The lengths of the longer end 322a and the shorter end 322b of the second antenna portion 30 are 20 mm and 1.5 mm, respectively, and the length of the transition portion 324 of the second antenna portion 30 is 1.5 mm, and the second antenna portion The shorter portion 326a and the longer portion 326b of 30 have lengths of 2.5 mm and 21.5 mm, respectively.

When the antenna structure 100 is in operation, the first antenna portion 10 can form a higher frequency (about 2600 MHz) resonant mode, and the second antenna portion 30 can form a lower frequency (about 2380 MHz) resonance. Modal. Since the first antenna portion 10 and the second antenna portion 30 have a specific distance (0.4 mm) therebetween, the current flowing through the first antenna portion 10 and the second antenna portion 30 is generated. Magnetic coupling can effectively improve higher harmonics The mode of the mode is matched with the lower frequency resonant mode to form an operating band of about 165 MHz. The operating band completely covers the Bluetooth communication frequency range (2.40 GHz - 2.485 GHz), so that the antenna structure 100 can be used for transmitting and receiving Bluetooth. Signal.

4 shows the Return Loss (RL) of the antenna structure 100 of the preferred embodiment of the present invention. Generally, the voltage standing wave ratio (VSWR) of the antenna is 2:1 as the frequency band used by the antenna, where the reflection loss value is equal to -10 decibels (dB), so the reflection loss value is less than or equal to -10 dB. The frequency range can be used as the frequency band for the antenna to operate.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and equivalent modifications or variations made by those skilled in the art in accordance with the spirit of the present invention are It should be covered by the following patent application.

100‧‧‧Antenna structure

210‧‧‧ end face

230‧‧‧ side

250‧‧‧ first plane

254‧‧‧Feeding end

200‧‧‧ base

220‧‧‧ top surface

240‧‧‧ gap

252‧‧‧ Grounding

260‧‧‧ second plane

Claims (8)

An antenna structure includes a first antenna portion and a second antenna portion, the first antenna portion including a first radiator, a first ground portion, and a first feed portion, the first The radiator is configured to transmit and receive a wireless signal having a first operating frequency, the second antenna portion includes a second radiator, a second ground portion, and a second feeding portion, wherein the second radiator is configured to transmit and receive a wireless signal of a second operating frequency, the first grounding portion and the second grounding portion are disposed in parallel, the first feeding portion is vertically connected to the second feeding portion, and the second radiator is parallel to the first The radiator is disposed and spaced apart from the first radiator by a length of the second feeding portion for causing a coupling effect between the first radiator and the second radiator to obtain the antenna structure A new working frequency band. The antenna structure of claim 1, wherein the first antenna portion is a planar inverted-F antenna. The antenna structure of claim 1, wherein the second antenna portion is a loop antenna. The antenna structure of claim 1, wherein the first radiator comprises a first connection portion, a second connection portion and a third connection portion, wherein the first connection portion is parallel In the third connecting portion, the second connecting portion is perpendicular to the first connecting portion and the third connecting portion. The antenna structure of claim 1, wherein the second radiator comprises a first meandering portion, a transition portion and a second meandering portion, wherein the first meandering portion and the second meandering portion are both In the shape of an elongated strip of "L" shape, the transition portion is connected between the first meandering portion and the second meandering portion. The antenna structure of claim 1, wherein the pitch is 0.4 mm. A wireless communication device includes a base body and an antenna structure. The base body is provided with a ground end and a feed end. The ground end and the feed end are connected to the antenna structure, and the improvement is as follows: the antenna structure The antenna structure according to any one of claims 1 to 6. The wireless communication device of claim 7, wherein an "L" shaped notch is formed in the base, and the first antenna portion and the second antenna portion are both disposed in the notch.